What is one of the criteria for exhaust systems during a Class D inspection?

During a Class D inspection, one of the primary criteria for exhaust systems is that they must be free of leaks. A well-functioning exhaust system is crucial for ensuring that harmful gases produced by the engine are effectively directed out of the vehicle, preventing them from entering the cabin. Additionally, leaks can lead to increased noise levels and contribute to environmental pollution. Inspectors will look for any signs of corrosion, cracks, or holes in the exhaust components that could indicate a leak. Ensuring the integrity of the exhaust system is important for the vehicle's safety and compliance with emissions regulations, contributing to overall public health and environmental protection.

The other options do not represent essential criteria for exhaust system inspections. For example, the sound produced by the exhaust system can vary widely depending on the vehicle model and modifications made, but it is not a standard criterion for inspection. Matching the exhaust system to the vehicle's model may consider performance but isn't a specific requirement during an inspection. While enhancing vehicle performance is an important aspect of automotive engineering, it is not a focal point during a standard inspection related to exhaust systems.